A tournament that belatedly came to life on Saturday, with Stan Wawrinka’s
heroic assault on Mount Djokovic, can now look forward to an intriguing
finale on Monday night.

While most romantics were rooting for Wawrinka to upset the world No1, his eventual defeat does at least mean that the two leading players of 2013 will contest the last grand slam of the year.

This might seem a touch unfair on Andy Murray, whose ghost-busting eclipse of Fred Perry at Wimbledon was unquestionably the moment of the season.

But while Murray has delivered some sublime performances, he is like the composer who has to wait for inspiration to arrive, popping up after a fallow period to unveil a new masterwork. Whereas Rafael Nadal and Novak Djokovic are more like Mozart and Bach: relentless in their productivity.

Nadal’s record on hard courts this year has been mind-boggling: 22 matches, 22 wins. And this on a surface that he has always complained about, because of the damage it inflicts on his irritable knees.

After the seven-month lay-off he took last year, which prompted many to write his epitaph as a grand slam contender, he has pulled off the most dramatic comeback since Gandalf.

As for Djokovic, he arrived in New York with three titles this year and an overall record of 44-8.

There were a couple of sloppy moments on his way to the final: a set dropped to Mikhail Youzhny and a nervous early phase against Wawrinka when he could barely land his serve. But then, when he comes up against Nadal, you might as well toss the form-book away.

These two have locked antlers 36 times, the most encounters between any two men in the open era, and their relationship has developed a compelling dynamic of its own. Logically speaking, there must have been some dull matches along the way ... but it is difficult to recall any.

“It’s a hard match to call, because Novak can flick a switch,” said Barry Cowan, the Sky Sports commentator and former British Davis Cup player.

“I remember at Wimbledon in 2011, I watched him struggle against Bernard Tomic in the quarter-final, and came close to writing him off. But then he got to the final and played like God to blow past Nadal in four sets.”

The movie trailer plot-lines would be complete if we could say that the world No1 ranking were at stake. In fact, Djokovic will hold on, by a fingernail, even if he loses.

Realistically, though, he cannot afford to do so because Nadal – who is not defending any points for the rest of the season – would probably overtake him at the very next tournament.

Nadal’s resurgence is connected to his sense of mortality, which he felt more keenly after seven months at home. In his autobiography, he predicted that he will not be happy once his career is finished, hence he wants to eke every last drop of performance out of his body while he still can.

To this end, he has amended his playing style to be more assertive. He wants to keep the points shorter and avoid significant footslogging.

In practical terms, this means fewer attritional cross-court rallies and more use of what is perhaps the most venomous ground-stroke in tennis – Nadal’s booming, dipping forehand down the line. In Montreal last month, this was the key weapon in his semi-final victory over Djokovic.

“Djokovic was a little bit surprised how much speed came from Rafa in that match,” said Francis Roig, Nadal’s part-time coach. “He was like: ‘What happened here, is there something different with this guy?’”

There was indeed. As John McEnroe observed in New York, “The top guys are always figuring out ways to get one or two per cent better.”

This is also true of Djokovic, whose new book Serve To Win reveals a man hungry to realise every ounce of his potential. Much of the text is devoted to his gluten-free diet, which he credits with his transformation from grand slam nearly-man to tennis’s top dog.

Some of his ideas might verge dangerously close to being new-age mumbo-jumbo, but at least he is prepared to try new things.

A good example is the hiring of Wojtek Fibak as his new assistant coach. The Polish top-ten player from the 1970s mentored the young Ivan Lendl.

“Somebody else might have been happy with being No1 and winning one grand slam this year,” Fibak told Telegraph Sport.

“But that is not up to his standard and he decided to include me in the team, to get some fresh ideas. In the back of his mind he would like to get back to the dominance he had in 2011.”

A win over the hottest player on the men’s tour would be a good start. But first Djokovic will have to find the intensity he lacked in the Wimbledon final, where – as Fibak accurately observes – “he was leading all the sets but lost all the important points”.

Murray took his chances on that memorable Sunday, and Nadal will hope to follow suit on Monday.